Wireless sensor apparatus

Abstract

A wireless sensor apparatus includes first and second polarization antennas whose polarization surfaces of radiation waves are mutually orthogonal, a first mixer circuit connected to the first polarization antenna and configured to input a first reception signal received by the first polarization antenna, a second mixer circuit connected to the second polarization antenna and configured to input a second reception signal received by the second polarization antenna, a signal generation circuit configured to generate pulse signals fed to the first and second polarization antennas and also supplied to the first and second mixer circuits, and a differential amplification circuit configured to perform a differential amplification on a mixed output obtained by mixing the first reception signal and the pulse signal by the first mixer circuit and a mixed output obtained by mixing the second reception signal and the pulse signal by the second mixer circuit.

1. A wireless sensor apparatus comprising:
 first and second polarization antennas whose polarization surfaces of radiation waves are mutually orthogonal; 
 a first mixer circuit connected to the first polarization antenna and configured to input a first reception signal received by the first polarization antenna; 
 a second mixer circuit connected to the second polarization antenna and configured to input a second reception signal received by the second polarization antenna; 
 a signal generation circuit configured to generate pulse signals fed to the first and second polarization antennas and also supplied to the first and second mixer circuits; and 
 a differential amplification circuit configured to perform a differential amplification on a mixed output obtained by mixing the first reception signal and the pulse signal by the first mixer circuit and a mixed output obtained by mixing the second reception signal and the pulse signal by the second mixer circuit. 
 
     
     
       2. The wireless sensor apparatus according to  claim 1 ,
 wherein the first polarization antenna is composed of a vertical polarization antenna, and the second polarization antenna is composed of a horizontal polarization antenna. 
 
     
     
       3. The wireless sensor apparatus according to  claim 1 ,
 wherein the first polarization antenna is composed of a right-handed circularly polarized wave antenna, the second polarization antenna is composed of a left-handed circularly polarized wave antenna. 
 
     
     
       4. The wireless sensor apparatus according to  claim 1 ,
 wherein the first polarization antenna and the second polarization antenna are integrated into one antenna apparatus. 
 
     
     
       5. The wireless sensor apparatus according to  claim 1 ,
 wherein the first and second polarization antennas commonly use a transmission antenna and a reception antenna. 
 
     
     
       6. The wireless sensor apparatus according to  claim 1 ,
 wherein the first and second polarization antennas are respectively separately provided with a transmission antenna for radiating wireless waves by being fed with the pulse signal and a reception antenna for receiving a reflected wave reflected from an object and outputting first or second reception signal.